Extruded Foam, now at Bunnings

 
  Thumpa Chief Train Controller

Location: That's on a need to know basis.
Hi all, just a follow up to my pervious post.

I've look up all stores in NSW who currently have the foam in stock, which are the following:

Bankstown
Belmont
Bonnyrigg
Castle Hill
Crossroads
Dural
Glendale
Greenacre
Kotara
Minchinbury
Narellan
North Penrith
Penrith
Seven Hills
Tamworth
Taree

All listed above have the two thicknesses 50mm & 30mm in stock however; quantity varied from store to store.
Price for the 50mm sheet $20 (FL#0811028 )
Price for the 30mm sheet $12 (FL#0811027 )

Thumpa

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  Prof_Klyzlr Station Staff

Hi all, just a follow up to my pervious post.

I've look up all stores in NSW who currently have the foam in stock, which are the following:

Bankstown
Belmont
Bonnyrigg
Castle Hill
Crossroads
Dural
Glendale
Greenacre
Kotara
Minchinbury
Narellan
North Penrith
Penrith
Seven Hills
Tamworth
Taree

All listed above have the two thicknesses 50mm & 30mm in stock however; quantity varied from store to store.
Price for the 50mm sheet $20 (FL#0811028 )
Price for the 30mm sheet $12 (FL#0811027 )

Thumpa
Thumpa

Dear thumpa,

You forgot my "locals", the Balgowlah and Belrose "full line" Bunnings...

Happy Modelling,
Aim to Improve,
Prof Klyzlr
  Thumpa Chief Train Controller

Location: That's on a need to know basis.
I can only see what the system shows me...
  Coastboy7 Locomotive Fireman

Can't see northern nsw on the list (ballina lismore Grafton) so I assume we are part of Qld in the bunnings world.  Can't find it on the web site for these stores.
  Thumpa Chief Train Controller

Location: That's on a need to know basis.
Can't see northern nsw on the list (ballina lismore Grafton) so I assume we are part of Qld in the bunnings world.  Can't find it on the web site for these stores.
"Coastboy7"


Please read the post made on Tuesday, locations, DC, and states etc. You can use the FL numbers to have your local store, order in from the stores which have been listed above in the pervious post. At this point in time, the only information on the Bunnings web site is a short Youtube video about the product.
http://youtu.be/WRBhbKvNBOI

Thumpa
  SAR523 Assistant Commissioner

Location: Chicago, IL
I did have a read of those links (blush).

I think this is probably important to keep in mind:  

"If the cable temperature can be kept relatively low (50–60°C for a 50% usage situation), the rate of migration will be slow and will not cause a problem over 50 years."

So Aaron is completely right that there's very little additional cost in sticking a straw down to insulate the wires so you may as well as intermittent shorts that develop would be maddening to debug (plus it makes your wires much easier to thread).  However if your layout is used anywhere near close to 50% of the time at temperatures near 50-60deg and lasts for over 50 years then my hat goes off to you (although it's not entirely clear to me whether it's just surface area contact that counts and what effect temperature has on the migration rate).

Lets assume you've got a large layout and you're carrying 10A in a 12AWG/2mm main bus.  From my back of the napkin (where I took a bunch of shortcuts but from memory it's not way off) that's going to to radiate less than 0.5C over ambient.  And your main bus likely hangs below the foam anyway and obviously the current and heating of individual feeders should be much lower and carry current a lot less often (except possibly in a yard with a bunch of sound locos idling).

That's not to say that certain non-building code foam may be a little more reactive to PVCs (e.g. your fruit packing material white foam) but that's just speculation.

I'm now a little interested in whether the standard 2 and 3 cable jacket used in the US are migration resistant as Styrofoam has been used in wall insulation for well over 30 years.  And it's common practice to embed power cables in it and I've never once heard of a short due to this.  It wasn't really an issue for me when I was reading up on the code as we have to use rigid metal conduit in the Chicago area (although that's a fire code, rather than a building code reg, to address fires started by mice and rats chewing power cables).   I also had to remove a switch from the layout recently that was installed around 7 years ago and looked very closely at the feeder droppers - I couldn't observe any deterioration in the jackets.  

However, as Aaron said, the cost of protection is pretty low.
  Dieselfan Locomotive Fireman

Hi

So can someone make it abundantly clear to a novice such as me, whether the foam by itself can support a layout.

By that I mean I have already constructed a ladder frame and overlaid it with ply. I bought sufficient 30mm foam to use as an underlay for the trackwork, but it is so straight, dimensionally accurate and rigid that I am thinking of dispensing with the ply baseboard.

Bad idea?

Regards
John
  danpickard Junior Train Controller

Location: Geelong
Hi John,
The foam is certainly more than strong enough for this purpose.  Unless you plan on using bricks to build up the scenery on top, the extruded foam sheet, supported by the timber frame underneath will be quite sufficient.  The ply could probably be left there if already mounted, but is just another layer to cut through with wiring (although the timber makes for an easier surface to mount things like point motors onto the underside with screws).  Plenty of exhibition layouts are fairly simple timber frame and foam construction, and quite capable of enduring the rigours of exhibition travel and set up.

Cheers,
Dan Pickard
  Dieselfan Locomotive Fireman

Thanks Dan.
Every step in building a layout seems to result in some kind of compromise.
Regards
John
  Aaron The Ghost of George Stephenson

Location: University of Adelaide SA
"If the cable temperature can be kept relatively low (50–60°C for a 50% usage situation), the rate of migration will be slow and will not cause a problem over 50 years."
"SAR523"
My anecdotal observation is that the recommendation contained there is flawed. I have seen cables that have hardly any use on layouts suffer reactions with XPS, and I have been thinking about this for some days as to why. Most industrial cabling has multiple layers of insulation, the inner core insulation and then the outer insulative layer surrounding the multiple conductors. Many model layouts just run the single conductor strands, often of 'hobby' grade flex which not being mains rated has thinner insulation and no outer sheath to further retard the damage from the foam.
  SAR523 Assistant Commissioner

Location: Chicago, IL
Hi

So can someone make it abundantly clear to a novice such as me, whether the foam by itself can support a layout.

By that I mean I have already constructed a ladder frame and overlaid it with ply. I bought sufficient 30mm foam to use as an underlay for the trackwork, but it is so straight, dimensionally accurate and rigid that I am thinking of dispensing with the ply baseboard.

Bad idea?

Regards
John
Dieselfan

One recommendation would be to add a thin 'skin' on the bottom (2-3mm or more) to attach screws into to hang, well, all the sorts of things you hang under layouts.  I didn't and I greatly regret this as you otherwise need to glue plates of wood on for tortoises, servos, wire bundle hangers etc.

The recommendation for supporting foam with a cross piece at least every 24"-36" from memory (google around, it's a very common building material in US layouts).  It is dimensionally sound but it is not structural as you can clearly see if you pick a sheet up.  It doesn't need as much support as ply as it doesn't shrink and expand over humidity and temperature.

Otherwise there is no problems with laying track or cork straight on it.  That's very common in the US.  Makes it really easy to dig trenches etc.  Just make sure you use a foam compatible adhesive (it'll say it on the tube) as there are plenty of adhesives that will eat right through the stuff.
  David Peters Dr Beeching

Location: "With Hey Boy".
You might want to check up on what adhesives in Australia though can be used for foam etc as American adhesives are not always available in Aust. And Also it might not be a requirement in Aust to list that a adhesive is suitable for foam. Best to check it out thoroughly here before buying your adhesive. In general water based adhesives will stick most foams together, but even some of these have other things in them that might eat the foam. Testing on some smaller pieces is always good advice though!
  Dieselfan Locomotive Fireman

Ok. I'll keep the ply. No big deal, I guess. Although top down drilling of feed holes for droppers will need an exceptionally sharp bit and a steady hand I reckon.

I was just going to use PVA to make the ply/foam sandwich. Aquadhere or something. Surely someone has tested that?

Another thing if I may, is paint. My research suggests that special paint is required. Latex or alkyd. Does anyone have comments on that? Sounds pretty messy. I was hoping that I could use a water based undercoat.

Regards
John
Appreciate your views.
  Aaron The Ghost of George Stephenson

Location: University of Adelaide SA
Drill the foam by hand, use your power drill to get through the timber if you're worried about the foam deck. The tearing of the foam at the beginning of a hole is not a big deal by the time you ballast etc anyway. You can probably neatly 'punch' a hole in your foam too, just use a suitable size nail and a hammer, test on a off cut and support the underside of the foam so it doesn't tear a chunk off.
  brett80 Station Staff

Thanks Dan for posting this.

For any Perth/WA readers, Rockingham Bunnings is stocking the foam now also. 30mm and 50mm thickness.

I've still got about a third of my layout to build so will definitely be using this material for that rather than kilos upon kilos of pine and ply like the rest of the layout!

Brett
  David Peters Dr Beeching

Location: "With Hey Boy".
You are still going to need some kind of support for the foam sheet though as by itself over long distance's it would not support much without sagging, cracking or snapping. You would be better off making a baseboard with a ply top but using it upside down to normal with the foam inserted into the space that is now the top. This would support the foam completely, and allow you to place things like point motors etc where ever you want without gluing pieces on that might later come adrift to support point motors etc. No glue is really 100% good for holding on especially when heavy things are used under a layout. The upturned layout board would probably be the best idea as it would only require a basic bit of either woodwork or metal work to make a basic frame.

A piece of foam just by itself is not the answer to your prayers unfortunately, as it would not give enough rigid support without some kind of frame around it and under it to support it. And if you are building a modular type layout a frame is a necessity to join sections together and have them come out nice and even etc. Bolts or clip's etc do not hold well in foam if they hold at all!
  LaidlayM Chief Commissioner

Location: Research
You are still going to need some kind of support for the foam sheet though as by itself over long distance's it would not support much without sagging, cracking or snapping. .....................
David Peters

Is this based on any experience David?

I have a friend about to try foam over a l girder frame, I think it will be fine without a sheet of ply.

Mark
  duttonbay Minister for Railways

I have a friend about to try foam over a l girder frame, I think it will be fine without a sheet of ply.
"LaidlayM"

I do too.
  David Peters Dr Beeching

Location: "With Hey Boy".
This was for the person who does not have a track plan envisioned as yet and wants to a sheet or two of foam, a sheet of ply under the foam would fully support the sheet of foam and allow one to lay the track any where that they liked and have something solid to screw point motors tunnel supports, catenary or what ever else on if needed. When I say ply, a sheet of 3 ply would be enough. Later though you can pre plan a layout to only need to have cross pieces to support the foam if needed, but after you have gained a bit of knowledge about the actual foam. I got the impression from reading a few of the posts on here that some wanted to get rid of the frame altogether and just use a sheet of foam. It would be possible but you would never be able to move it though with out something supporting it. It was just an alternative for those that wanted to use foam but did not have a track plan in mind at the start.

Model Railroader did a layout like this a while back to make it simple for a beginner or novice to make their 6 X 4 dream layout using foam as the main scenery base and upward! Not saying it is the only way though just a suggestion  for a novice!
  LaidlayM Chief Commissioner

Location: Research
This was for the person who does not have a track plan envisioned as yet and wants to a sheet or two of foam, a sheet of ply under the foam would fully support the sheet of foam and allow one to lay the track any where that they liked and have something solid to screw point motors tunnel supports, catenary or what ever else on if needed. When I say ply, a sheet of 3 ply would be enough. Later though you can pre plan a layout to only need to have cross pieces to support the foam if needed, but after you have gained a bit of knowledge about the actual foam. I got the impression from reading a few of the posts on here that some wanted to get rid of the frame altogether and just use a sheet of foam. It would be possible but you would never be able to move it though with out something supporting it. It was just an alternative for those that wanted to use foam but did not have a track plan in mind at the start.

Model Railroader did a layout like this a while back to make it simple for a beginner or novice to make their 6 X 4 dream layout using foam as the main scenery base and upward! Not saying it is the only way though just a suggestion for a novice!
David Peters

So do you now retract your statement about sagging and cracking?

Mark
  Hendo Deputy Commissioner

Is this based on any experience David?

I have a friend about to try foam over a l girder frame, I think it will be fine without a sheet of ply.

Mark
LaidlayM

My father has had a sheet of the blue 50mm Styrofoam up on the rafters in his garage awaiting a layout for about three or four years now, it is sagging, and has been doing so for about 2 1/2 to 3 1/2 years. So yes it does need a simple support frame, wood or aluminium.

If you need larger sizes I would still go with the other brands, the Knauff sheets Bunnings is selling seem terribly expensive, plus, if the have sold you a sheet or two, the industrial sellers will often let you take whatever you want out of their scrap bins.

Cheers,
Hendo
  LaidlayM Chief Commissioner

Location: Research
My father has had a sheet of the blue 50mm Styrofoam up on the rafters in his garage awaiting a layout for about three or four years now, it is sagging, and has been doing so for about 2 1/2 to 3 1/2 years. So yes it does need a simple support frame, wood or aluminium.

If you need larger sizes I would still go with the other brands, the Knauff sheets Bunnings is selling seem terribly expensive, plus, if the have sold you a sheet or two, the industrial sellers will often let you take whatever you want out of their scrap bins.

Cheers,
Hendo
Hendo

Good to hear of some real world experience.  What's the spacing between supports, the rafters themselves would be 450-500 apart I guess.

Mark
  David Peters Dr Beeching

Location: "With Hey Boy".
So do you now retract your statement about sagging and cracking?

Mark
LaidlayM

Where in the hell did I retract anything at all. I have simply stated that which ever way you use it you have to provide some support to it either way. People today cannot read simple things without adding things to it. Some on here leave me speechless at the best of times!

Any fool knows that if you have a long enough piece of foam or even board that is not supported underneath somehow it will sag and if left like it, it will eventually crack or break off, the board might not break off but it could crack though! Even man made boards etc will sag or bend if not supported properly.  Steel will even bend (Arc) in long pieces if not supported fully!
  LaidlayM Chief Commissioner

Location: Research
Where in the hell did I retract anything at all. I have simply stated that which ever way you use it you have to provide some support to it either way. People today cannot read simple things without adding things to it. Some on here leave me speechless at the best of times!

Any fool knows that if you have a long enough piece of foam or even board that is not supported underneath somehow it will sag and if left like it, it will eventually crack or break off, the board might not break off but it could crack though! Even man made boards etc will sag or bend if not supported properly. Steel will even bend (Arc) in long pieces if not supported fully!
David Peters

David, you need to read more carefully, it was a question (with question mark at the end) not a statement.

I am not looking for what any fool knows, I want to hear of real world experience.

Mark
  miktrain Deputy Commissioner

Location: Adelaide SA
I forgot my personal favourite, the black poly, irrigation type pipe, hardware stores will sell you metres of it for bugger all, and if the normal 9 or 12 mm or whatever it is size is too small, they'll have 25 mm for not much more.
Aaron

You mean offcuts from my sprinkler installs (19mm) just like on Paradigm

Tony

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